The built WordPress source, licensed under the GNU General Public License version 2 (or later), can be browsed online or checked out locally with Subversion or Git:

Subversion: https://core.svn.wordpress.org/

Git mirror: git://core.git.wordpress.org/

WordPress minifies core JavaScript files using UglifyJS and CSS using clean-css, all via the Grunt JavaScript-based task runner. The development source that includes un-minified versions of these files, along with the build scripts, can be browsed online or checked out locally with Subversion or Git:

Subversion: https://develop.svn.wordpress.org/

Git mirror: git://develop.git.wordpress.org/

The source code for any program binaries or minified external scripts that are included with WordPress can be freely obtained from our sources repository.